On Designs of Decentralized Reputation Management for Permissioned Blockchain Networks

In permissioned blockchain networks,the Proof of Authority(PoA)consensus,which uses the election of authorized nodes to validate transactions and blocks,has beenwidely advocated thanks to its high transaction throughput and fault tolerance.However,PoA suffers from the drawback of centralization dominated by a limited number of authorized nodes and the lack of anonymity due to the round-robin block proposal mechanism.As a result,traditional PoA is vulnerable to a single point of failure that compromises the security of the blockchain network.To address these issues,we propose a novel decentralized reputation management mechanism for permissioned blockchain networks to enhance security,promote liveness,and mitigate centralization while retaining the same throughput as traditional PoA.This paper aims to design an off-chain reputation evaluation and an on-chain reputation-aided consensus.First,we evaluate the nodes’reputation in the context of the blockchain networks and make the reputation globally verifiable through smart contracts.Second,building upon traditional PoA,we propose a reputation-aided PoA(rPoA)consensus to enhance securitywithout sacrificing throughput.In particular,rPoA can incentivize nodes to autonomously form committees based on reputation authority,which prevents block generation from being tracked through the randomness of reputation variation.Moreover,we develop a reputation-aided fork-choice rule for rPoA to promote the network’s liveness.Finally,experimental results show that the proposed rPoA achieves higher security performance while retaining transaction throughput compared to traditional PoA.

A Deletable and Modifiable Blockchain Scheme Based on Record Verification Trees and the Multisignature Mechanism

As one of the most valuable technologies,blockchains have received extensive attention from researchers and industry circles and are widely applied in various scenarios.However,data on a blockchain cannot be deleted.As a result,it is impossible to clean invalid and sensitive data and correct erroneous data.This,to a certain extent,hinders the application of blockchains in supply chains and Internet of Things.To address this problem,this study presents a deletable and modifiable blockchain scheme(DMBlockChain)based on record verification trees(RVTrees)and the multisignature scheme.(1)In this scheme,an RVTree structure is designed and added to the block structure.The RVTree can not only ensure that a record is true and valid but,owing to its unique binary structure,also verify whether modification and deletion requests are valid.(2)In DMBlockChain,the multisignature mechanism is also introduced.This mechanism requires the stakeholders’signatures for each modification or deletion request and thus ensures that a record will not be modified arbitrarily.A user’s request is deemed valid only if it is dually verified by the RVTree and the multisignature mechanism.The analysis finds that DMBlockChain can provide a secure and valid means for modifying and deleting records in a block while ensuring the integrity of the block and that DMBlockChain can effectively save space in some scenarios that require frequent records modification.

Repurposing EV Batteries for Storing Solar Energy

1.Introduction Carbon neutrality has emerged as a global goal due to its pivotal role in addressing the challenges of global climate change.Before the United Nations Climate Summit was held in November 2020,124 countries promised to reach net-zero emissions[1].Solar energy is one of the important renewable energy sources that significantly curtail carbon emissions originating from fossil fuels.

Research Progress on Refractory Hypertension in Traditional Chinese Medicine

At present,the mortality rate and disability rate caused by cardiovascular and cerebrovascular diseases are very high in China.Individuals with refractory hypertension are at a greater risk of developing chronic kidney disease,heart failure,stroke and myocardial infarction.Therefore,how to effectively control blood pressure and identify the cause of refractory hypertension is a problem that medical workers need to solve,and it is also the key to prevent cardiovascular disease.In recent years,the government actively supports the development of traditional Chinese medicine.Since the curative effect of traditional Chinese medicine is recognized by the public,the prospect of traditional Chinese medicine in the prevention and treatment of refractory hypertension is considerable,and it is expected to become the main key research direction in the future.

High-performance terahertz modulators induced by substrate field in Te-based all-2D heterojunctions

High-performance active terahertz modulators as the indispensable core components are of great importance for the next generation communication technology.However,they currently suffer from the tradeoff between modulation depth and speed.Here,we introduce two-dimensional(2D)tellurium(Te)nanofilms with the unique structure as a new class of optically controlled terahertz modulators and demonstrate their integrated heterojunctions can successfully improve the device performances to the optimal and applicable levels among the existing all-2D broadband modulators.Further photoresponse measurements confirm the significant impact of the stacking order.We first clarify the direction of the substrate-induced electric field through first-principles calculations and uncover the unusual interaction mechanism in the photoexcited carrier dynamics associated with the charge transfer and interlayer exciton recombination.This advances the fundamental and applicative research of Te nanomaterials in high-performance terahertz optoelectronics.

顺德德胜体育中心游泳馆单层马鞍形索网设计分析

顺德德胜体育中心为在国内沿海台风高发区首次采用单层马鞍形索网结构的工程。索网平面为109 m×71 m的椭圆,索网矢高8 m,索网屋面钢结构的支撑体系和抗侧力体系由外围V支撑和屋面环梁共同组成。索网结构纵向受力索和横向稳定索分别采用2ϕ65和2ϕ45高强密封索,环梁为截面1 m×2 m的巨型矩形梁,屋面系统为三层膜面体系。作为沿海强台风地区的马鞍形索网屋盖,必须通过精细找形和找力确定主索和次索的预拉力,紧密协调“恒载+活载”和“恒载+风载”组合下挠度和索内力的相对比例,使得向上和向下的变形相对平衡。结构体系和找形找力初步确定后,通过静力分析、稳定性分析、防连续倒塌分析、施工模拟分析以及罕遇地震弹塑性分析,进行构件精细化设计并验证结构方案的合理性。索网安全冗余度和施工次序对结构体系的成型至关重要,设计采用非线性静力分析方法进行断索分析,并从工程设计角度建议采用高空溜索+张拉稳定索的张拉方案。针对结构受力特点,周边V撑承受较大双向轴力,且外露可视,故创新性采用双向推力轴承节点,在保证结构受力同时确保建筑美观性,同时确保节点安全和冗余度。屋盖钢结构和索结构设计均能满足GB 50017—2017《钢结构设计标准》的要求,并能有效实现建筑形态。

Integrative cancer genomics： models, algorithms and analysis

In the past decade, the remarkable development of high-throughput sequencing technology accelerates the generation of large amount of multiple dimensional data such as genomic, epigenomic, transcriptomic and proteomic data. The comprehensive data make it possible to understand the underlying mechanisms of biology and disease such as cancer systematically. It also provides great challenges for computa- tional cancer genomics due to the complexity, scale and noise of data. In this article, we aim to review the recent develop- ments and progresses of computational models, algorithms and analysis of complex data in cancer genomics. These topics of this paper include the identification of driver mutations, the genetic heterogeneity analysis, genomic markers discovery of drug response, pan-cancer scale analysis and so on.

BMTK： a toolkit for determining modules in biological bipartite networks

Background： Module detection is widely used to analyze and visualize biological networks. A number of methods and tools have been developed to achieve it. Meanwhile, bipartite module detection is also very useful for mining and analyzing bipartite biological networks and a few methods have been developed for it. However, there is few user- friendly toolkit for this task. Methods： To this end, we develop an online web toolkit BMTK, which implements seven existing methods. Results： BMTK provides a uniform operation platform and visualization function, standardizes input and output format, and improves algorithmic structure to enhance computing speed. We also apply this toolkit onto a drug-target bipartite network to demonstrate its effectiveness. Conclusions： BMTK will be a powerful tool for detecting bipartite modules in diverse bipartite biological networks. Availability： The web application is freely accessible at http：//www.zhanglabtools.net/BMTK.

珠海新航展馆钢结构选型和设计

作为珠海航展的主展示馆,航展馆屋盖造型新颖,柱位规整,且屋盖结构外露可见,优选建筑美观、受力合理的结构形式——空间四角锥网架+入口巨型桁架组合体系;根据机库门的不同开启模式设计4种不同工况用于风洞试验及后期设计,确保复杂风环境下的结构安全。根据结构特点,分别对屋盖结构形式、分缝做法、网架高度、球节点做法进行技术和经济比较。根据建筑功能,首次在机库门上方设置三层立体桁架体系,上面两层与网架连接,下弦层作为贵宾厅的建筑使用层,利用机库门两侧的竖向交通空间设置立体桁架柱,与机库门上方的桁架梁构成整体结构刚度。从受力考虑,屋盖设置两道结构缝,分析屋盖传力路径,入口桁架承担了屋盖总荷载的85%。由于结构分缝的关系,网架受力应尽可能往机库门方向传递。采用人工干涉力流理念,对靠近机库门附近的网架横向弦杆进行局部抽空,利用刚度效应使得屋盖力流优先传至巨型桁架结构,满足力流控制需要。在满足舒适度需求下,对上人贵宾厅在不同行走路径下进行了舒适度分析。在满足不停航施工的严苛现场条件下,采用了“超大型构件液压同步提升技术”对整体结构分两次提升的方案。在满足安全、经济、美观的前提下,选择了合理的结构方案,并进行了连接节点设计。本工程用钢量适中,同时圆满完成了工期和成本方面的预期目标,取得了显著的社会和经济效益。